Parallel jaw pliers



June 1954 A. R. SPIKINGS PARALLEL JAW PLIERS 2 Sheets-Sheet 1 Filed Nov. 26, 1951 INVENTOR ALBERT R. SPIKINGS ATTORNEY A. R. SPIKINGS PARALLEL JAW PLIERS June 1, 1954 2 Sheets-Sheet 2 Filed Nov. 26 1951 ATTORNEY Patented June 1, 1954 UNITED STATES PATENT OFFICE PARALLEL JAW PLIERS Albert R. Spikings, River Grove, Ill.

Application November 26, 1951, Serial No. 258,120

4 Claims.

The present invention relates to clamping devices and more particularly to that class of parallel jaw devices which areapplicable to pliers, forceps, Vises, wrenches and the like.

This invention has reference to improvements in and relating to parallel jaw devices of the kind in which a pair of jaws are constructed and arranged to open and close in substantially parallel relationship, as distinct from pivotally swinging through an angle, in order to perform their gripping, crushing, cutting, perforating or other function.

The primary object of the invention is to provide a parallel jaw or vise grip pliers constructed in a simple manner by having a sliding jaw which is a self-parallel closing jaw that gives a full surface grip.

Another object of the invention is to provide a parallel jaw pliers wherein the jaws are relatively movable in sliding rectilinear fashion.

A still further object of the invention is to provide a parallel-jaw or vise-grip pliers which is of sturdy construction wherein the jaws are mutually supported and guided during operation.

A more complete understanding of the invention may be had by reference to the following description when considered in conjunction with the accompanying drawings, wherein,

- Fig. l is an elevational view of the pliers, according to the present invention, in closed position;

Fig. 2 is a sectional view of the pliers taken on line 2-2 of Fig. l, and

Fig. 3 is an elevational view of the pliers in open position. I

Having reference to Figs. 1, 2, and 3 of the drawings, the upper handle portion H is preferably of U-shaped construction and substantially of the contour or conformation shown. Spanning the flanges at the forward end of the handle portion l i is the fixed gripping surface or jaw l2. Confronting jaw l2 and cooperating therewith is the gripping surface l3 of a movable jaw M. The confronting faces or surfaces l2 and i3 of the jaws may be either smooth, knurled, serrated or otherwise toothed to suit various purposes. Moreover, the gripping surfaces l2 and it may extend or project beyond the sides of the jaws as at l5 and it, so as to slide scratch-proof caps thereover, or other-purpose caps. For example, rubber or felt may be glued to a metal cap, which may in turn slide over the jaw teeth so that the pliers may be used to hold airplane parts or patterns without scratching them.

The movable jaw it is supported in one manner in parallel motion fashion by two pairs of parallel motion links [l and it, one pair located on each side of the pliers. The movable jaw 14 is also supported in a further manner, according to the invention, by a pressure support [9. The feature of the invention resides in providing effective cooperating facilities or means between the movable jaw l4 and the pressure support I9, whereby the jaw or gripping surfaces l2 and 53 are constantly maintained in substantially parallel relationship in all relative positions of the laws.

The support I9 is positioned inside the portion ll between the flanges thereof and is supported pivotally by a pivot 21 journalled in the sides or flanges of the portion H. Likewise, the support [9 is positioned between the side walls of the movable jaw M (Fig. 2). The side walls of the jaw [4 are provided on the inside surfaces thereof with identical confronting semi-circular grooves 22 and 23, while the pressure support 19 is provided on each side thereof confronting said grooves, with corresponding semi-circular ribs or flanges 24 and 25, adapted to slidably fit into said grooves 22 and 23, respectively.

Pivotally articulated to the support H! at 26 is a lower handle portion 21, which is proportioned substantially as shown to give a compact grip and great pressure with ease of operation. Pivotally connected to the lower handle 21 at 28, and positioned to afford a toggle effect is a toggle link 29. The lower handle 21 is of U-shaped conformation and is adapted to be operable within the upper handle portion l I. The toggle link 29, in turn, is adapted to operate within the U-shaped conformation of lower handle 21. The other end of toggle link 29 is pivotallyconnected at 3| to a swivel member or fulcrum 32 which is swivelly connected to an adjusting bolt 33 threadedly carried in the end of the upper handle portion I l. Bolt 33 is provided with a knurled head 34 for easy turning. With the adjustable fulcrum 32, the maximum toggle effect is secured in all relative positions of the jaws.

With the arrangement of the fixed and movable jaws, aocording to the invention, the pressure support IS on which the movable'jaw H3 is supported carries the pressure load to the full opening of the pliers by virtue of thetongue and groove arrangement-comprising the semi-circular grooves 2223 and cooperating ribs 2425; the parallel relationship between the jaws being governed by the parallel motion links H and H3. The ribs 24 and 25 may be tapered as suggested in the drawings, to assure said parallel relationship of the jaws.

As an example of the relative proportions of the structure shown, and assuming that the radius 4| of the grooves 2223 from the line of the gripping surfaces of the pliers is unity or I, the distance 42 of the pivot 2| from the center of radius 4! is substantially three times the radius 4|. The distance 43'of the pivot 2| below the line of the gripping surface is substantially one-halfof theradius 4|. The distance 3 44 of pivot 45 of link I! in back of the pivot 2| is substantially one-half of distance 43, and the distance 46 of pivot 45 below pivot 2| is substantially three times the distance 44.

If desired, a spring (not shown) may be installed between handles II and 21 to hold the jaws open, or automatically open handle 21. By means of the adjusting screw 33, the device according to the invention can be used as a wrench, because by moving the pivot 3| in or out, lengthwise of the handle portion H, by the turning of the adjusting screw 33, the support [9 can be rotated about its pivot 2|.

In the operation of the device shown, the swinging of lower handle 21 away from the upper handle portion II will cause the pressure support to rotate counterclockwise about its pivot 2|. By means of links I! and I8, the movable jaw is held in parallel relationship with the upper jaw. However, the relative movements of jaw I4 and support I9 cause the ribs 24-25 to slide in the grooves 22-23 without binding. Thus, the jaw 14 is at all timessupported by the ribs 24-25. Then, when the lower handle portion 21 is moved toward the upper handle H, the support I9 is forced in a clockwise direction under the toggle action of handle 2'! and toggle link 29, in which event the pressure or load is taken up by the ribs 24-25 cooperating with the grooves 22-23.

Moreover, the ribs 24-25 carry the load Without undue strain on the links, similar to a crowbar applied between two bolts, and a crowbar effect is produced by the diametrically opposite ends of the semi-circular ribs 24-25 acting in the grooves 22-23. This crowbar effect between the pressure support l9 and the jaw [4 through the medium of ribs 24-25 operating in the grooves 22-23 enhances the mechanical advantage of the pressure support I9, since the length of the handles H and 21 are very much greater than the diameter of the semi-circular ribs 24-25.

It is, of course, understood that the links I! and [8 each have one end riveted to the jaw 14 and one end riveted to the handle H, and that these links I! and 18 must be parallel. It is further understood that in large pliers, rollers may be installed in the bed of ribs 24 and 25. The structure of the pliers is not limited to the design shown, but may be made heavier at all points if desired, and the edges may be made more rounded without deviating from the inventive idea.

In connection with the toggle link 29 the sharp point indicated by the numeral locks against the inside of lower handle 21 when the pliers is in an open position so that the pliers can be used as a wrench. The toggle link 29 is provided with a projection 52 which is adapted to bear against the lower handle in closed position to act as a stop and to maintain the centers 25,

.28 and 3| in a straight line.

a movable jaw portion, a support for said movable jaw portion mounted pivotally in said fixed jaw portion, said movable jaw portion and said support having cooperating semi-circular tongue and groove facilities effective as a force transferring means in all relative positions of said jaw portions, and parallel motion means for guiding said movable jaw portion parallelly with respect to said fixed jaw portion.

2. A tool having in combination, a handle provided with a stationary jaw portion, a movable jaw portion, a support for said movable jaw portion pivotally mounted in said handle, toggle instrumentalities articulated to said support and said handle, said movable jaw portion and said support having cooperating arcuately conformed tongue and groove facilities effective as a force transferring means in all relative positions of said jaw portions, parallel motion means for guiding said movable jaw portion parallelly with respect to said stationary jaw portion, and a hand engaging portion operably associated with said toggle instrumentalities, whereby a clamping force is imparted through said toggle instrumentalities and said force transferring means to said movable jaw portion.

3. A tool having in combination, a handle provided with a stationary jaw portion, a movable jaw portion, a support for said movable jaw portion pivotally mounted in said handle, a fulcrum in said handle, toggle instrumentalities articulated to said support and said fulcrum, said movable jaw portion and said support having cooperating arcuately conformed tongue and groove facilities effective as a force transferring means in all relative positions of said jaw portions, parallel motion means for guiding said movable jaw portion parallelly with respect to said stationary jaw portion, a hand engaging portion operably associated with said toggle instrumentalities, whereby a clamping force is imparted through said toggle instrumentalities and said force transferring means to said movable jaw portion, and means for adjusting said fulcrum to secure the maximum toggle effect in all relative positions of said jaw portions.

4. A tool having in combination, a handle provided with a stationary jaw portion, a movable jaw portion, a support for said movable jaw portion pivotally mounted in said handle, toggle instrumentalities articulated to said support and said handle, said movable jaw portion and said support having cooperating tongue and groove means effective as a force transferring means in all relative positions of said jaw portions, parallel motion means for guiding said movable jaw portion parallelly with respect to said stationary jaw portion, and a hand engaging portion operably associated with said toggle instrumentalities, whereby a clamping force is imparted through said toggle instrumentalities and said force transferring means to said movable jaw portion.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,086,078 Palmer Feb. 3, 1914 1,717,726 McGill June 18, 1929 2,379,107 Scheck a- June 26, 1945 2,417,013 Petersen Mar. 4, 1947 2,443,153 Wells June 8, 1948 2,481,435 Meunier Sept. 6, 1949 2,519,630 Boyer Aug. 22, 1950 2,553,400 Blair May 15, 1951 

